Electromagnetic device.



M. F. GEBR L R. C. LEAKB.

ELBGTROMAGNETIG DEVICE.

APPLICATION FILED OUT. 26, 1911.

Patented Sept. 2, 1913.

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M. F. GBER 6a R. C. LEAKE. ELBGTROMAGNETIU DEVICE.

APPLICATION FILED 00T. ze, 1911.

1,071,905. Patented sept. 2,1913.

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iflllll COLUMBIA PLANQGRAPH Co..wAsH1NGToN. D. c.

UNITED sTATEs PATENT oEEioE.

MAURICE F. GEER AND RICHARD C. LEAKE, OF ROCHESTER, NEW YORK, ASSIGNORS TO GENERAL RAILWAY SIGNAL COMIANY, OF GATES, YORK, A CORPORATION OF NEWV YORK.

Application le'd October 26, 1911.

To all whom t may concern.'

Be it known that we, MAURICE F. GEER and RICHARD C. LEAKE, citizens of the United States, and residents of the cit-y of Rochester, in the county of Monroe and State of New York, have invented a new and useful Electromagnetic Device, of which the following is a specification.

This invention relates to an electro-magnetic device.

The primary object of this invention is to increase the efficiency of an electro-magnetic device.

A further object of this invention is to decrease the friction produced by the movement of a movable member of an electromagnetic device.

A further object of this invention is to produce a support for the movable element of an electro-magnetic device which will offer no resistance to the movement of the movable element.

In electro-magnetic devices as heretofore constructed in which a movable armature has been employed, it has been customary to mount the armature upon a pivot pin which was cone shaped at both ends and which was held in place by two screws passing through fixed objects and having a conical cavity in their ends. lVhen such a construction is employed, it is necessary to have the pivot pin and the supporting screws made of dissimilar metals in order to reduce friction to a minimum and this has resulted in making the screws of brass and the pivot pin of steel as being the most readily available materials.

Even if the screws are not made of brass they must be made of a non-magnetic material in case the fixed object through which they pass is connected in any way with the magnetic circuit of the electro-magnetic device for if the screws are connected with the magnetic material of the electro-magnetic device they would, by reason of their magnetic attraction for the steel pivot pin prevent the armature from moving freely. This on first thought may appear to be far fetched, but in actual practical operation, it has been found to be of serious moment. It is also necessary when such a construction is employed in order to prevent wabbling of the armature to bind the pivot pin quite closely between the screws thus introducing Specification of Letters Patent.

ELECTROMAGNETIC DEVICE.

Patented Sept. 2, 1913.

Serial No. 656,938.

a considerable friction, and it has also been found that on account of the expansion and contraction caused oy difference of tempera- .ture that it is an extremely diliicult matter to so adjust the tightness of the screws upon the steel pivot pin that it will not be bound so` tightly that itwill not move at all in eX- tremely hot weather in case the adjust-ment happens to be made in cold weather.

An electro-magnetic device employing a movable armature, in order to operate at the greatest eiiiciency should have the least possible air gap in the magnetic circuit but with the construction above mentioned, due to the fact that the pivot pin on which the armature is supported is held in place by brass screws, an undesirable gap in the magnetic circuitis introduced which, by applicants7 method of construction is avoided, as will be hereafter pointed out.

In describing the invention in detail, reference will be had to the accompanying drawings, on which like characters of reference refer to like parts, and in which applicants have shown a preferred form of mechanism embodying the principle of their invention, and in which:

Figure l is a front elevation of an electromagnetic device. Fig. 2, is a side elevation of an electro-magnetic device. Fig. 3, is an enlarged detail cross sectional view upon the line A-B of Fig. l. Figs. 4, 5 and 6 are detail views of a knife edge bearing employed in the electro-magnetic device.

Applicant-s have embodied the principle of their invention in an electro-magnetic device commonly known as an electric bell, which is shown in front elevation by Fig. l, in which, l designates a mounting plate, which as best shown by Fig. 2, has outstanding lugs 2, formed integral therewith and through which pass screws 3, which pass through the bell mounting strip 4, and into the iron yoke 5, supporting the bell mounting strip 4 and the yoke 5 firmly in place.

The bell mounting strip 4 has at either end the gongs 5 and 6 attached thereto by means of screws 7. The iron yoke 5 has slots 8 and 9 near either end which extend into screw threaded holes l0 in the yoke; 11 and 12 designate iron cores which are screw threaded on their upper end and which are screwed into the threaded holes in the yoke 5 and which are clamped in adjusted position by means of the s-crews 13 which act to narrow the slots 8 and 9 and so bind the cores in place; 14 designates a screw which passes through the yoke 5 and is screwed into the iron or steel member 15, which bears upon its lower end the knife edge bearing' 16, shown in detail by Figs. 4, 5 and 6,

which is 'attached thereto by means of the c screw 17, which screw ,alsol supports the angularly bent member 18; 19V designates an armature which has a V shaped groove 20' .formed 'therein and which bears fagainst theA knife edge bearing 16, and has awmember 21 screwed into it and `rtherefore adjustable, which lmem-ber has a cone shaped cavity shaped -at its upper end and resting in the cone shaped cavity in the -member 21 andl headed at its lower' vfend and rest-ing upon the .resilient lmember 23, which Aresilient -mem-y ber is supported at either end b y means of screws 24 and 25, which are screw :threaded into the member 18, there being a lock nut on leach screw `to retain it iin vadjusted position. It will be noted that the ymember 23 is vbowed slightly as it exerts, an upward` tension upon the pin 22, and that the tension exerted by the member 23 upon 'the pin 22 can be varied yby screwing in orv'out the screws 24 vand 25.

Each end of the member 18 has an insulating sleeve 34 passed therethrough which has a hole passing therethrough which is screw threaded, and into which is threaded the screws 27 and 28, and upon each screw are nuts 29 and 30 which `hold the-terminals of the wires 31 and 32 in contact with the screws 27 and 28 and actas lock nuts for screws 27 and 28. Two vflat springs 33 and 34 lie directly over the ends of frthe screws 27 Vand 28 and are riveted by rivets 35 and 36 respectively to the armature 19, one kof the springs 34, as shown in Fig. 1, normally resting against the end of vscrew 28, it is practically immaterial however whether one or both of the springs rests against the screws.

The `ineinber 21 which is screw threaded into the larmature 19 has a projecting end -37 which is drilledto receive the `rod 38,V

which bears upon its upper end the 'hammer 39 adapted to strike lthe gongs 5 and 6 'as it is moved back and forth by the oscillation ofthe armature 19. The vcores 11 and 12 have wound upon them the wires 32 and 31 respectivelywhich are joined together at 'the upper -end by being .placed under the binding Vscrew 40, and wire 41 leads from vthe binding screw 40 to the terminal 42 to which the wire from the source of current is led to the electro-magnetic device; .the

other terminal Afrom the source being con?y nected to the binding post 43, and the binding post 43 4being connected by the wire 44 to the gong support 4v thus grounding it upon the frame vof the electro-magi'ietic device. Y

The operation of thedevice is as follows:

- Current entering at the binding post 42 passesthrough wire 41 to the binding post 40 'thence by wire 32.to the screw 28, thenceto the spring 34 and through the metal frame to the go-iig support 4 and then by wire 44 to binding post 43 and :to the other termina-l of the source of current. Current flowing in the above vt-raced path vcauses the righ'tha'nd end of the larmature 19, as viewed in Fig. 1, to be raised, thereby :causing the hammer 39 to strikel against the left 4hand gong 6, but the upward movement of the armature causes the spring 34 to ybreak-contact with screw 28 and at the `same time the spring 33 is brought into contact with screw 27, 'thus completing a circuit from the binding post 40 -through wire 31, screw 27, spring 33 and metal frame to the binding Ipost 43, so `that the left hand end of `armature 19 is -then attracted by the core 12 causing the vhammer 39 to strike the right hand gong 5, this of course causes spring 34 to vagainvmake contact with screw 28 and the aotionsare vthen repeated as long as current'is fed to the device.

It vis to be noticed that -the wires 32 and 31 are so wound upon the -cores 12 and 11,

.that when current -iows -through them the lower ends ofy -the cores will always have the same polarity which we will call south, as indicated on Fig. 1. 4t is also to be observed that thefarmature 19 is vindirect niag- `netic ycontact with the knife edge vbearing 16, which isformed of magnetic material -and that the knife edge lbearing. 16 is in directl magnetic `contact with `the body 15 which is also made of magnetic Vmaterial and that Vthe body '15 is vin direct magnetic contact with the yoke 5, which is of magnetic lmaterial andlthat the yoke 5 as is customary is in direct magnetic contact with the cores 11 and 12, so that when current flows through either coil `of wire 31 or 32 a magnetic flux is generated vin cores 112 or 11 which passes down through member 15, knife edge bearing 16 andlarinature 19 to the lower end of the Tpoles, so that the only air gap which occurs in the magnetic circuit is that which `occurs between the ends Iof the armature 19 and the ends of the cores 11 and 12. Such construction produces an extremely eilicient electro-magnetic device, for a comp'lete path for the magnetic iiuX through magnetic material is formechexcept at `the one :place where the flux must passthrough air vin order to enable the movment of the armature to takeL place and as thesanie -coiiditions hold as regards the magnetic y,flux generated fby both coils the device i'sequally eiicient on both sides.

As the armature 19 oscillates upon a knife edge, it is without friction, consequently, the armature has the freest possible movement both when being drawn toward the poles and when returning to normal position, furthermore the method of support herein employed allows the armature to move from its normal position without in any way increasing the tension of the member' supporting the armature, for the member 22 terminates exactly in line with the edge of the knife edge bearing so that whatever oscillation takes place no movement of the part or point of the armature against which rests the pin 22 takes place. It is also readily seen that the member 23 can be so adjusted by movement of the screws 24 and 25, as to exert any desired pressure upon the member 22.

Although applicants have herein shown and described their invention as embodied in an electric bell of the non-polarized direct current type, it is to be distinctly understood that applicants invention in its broadest aspect, may be embodied in various electro-magnetic devices as, for instance, thc ordinary alternating current electric bell, in which case springs 33 and 34 wouldbe dispensed with and the two coils upon the two cores would be in series and the source of alternating current would be connected directly to the free ends of the coils, thus forming a construction which is well understood and known to those skilled in the art. In such case, however, it would be necessary to polarize the armature 19, which would be in applicants form of invention herein shown an eXtremely simple mat-ter, for the member 15 would be, in such case, formed as a permanent magnet having its lower end formed as, say, a north pole, and the alternate flow of current through the coils would alternately cause the lower ends of the cores 11 and 12 to assume an opposite polarity to that of the lower end of member 15 thus causing an oscillation of the armature 19 in a manner well understood. It is also to be observed that in such case the magnetic flux through member 15 would always be in the same direction, thus tending to build up the permanent magnetism, rather than to destroy it. It is also to be understood that applicants invention is applicable to a relay device, that is to say, a contact maker could be attached to the rod 38 so as to complete or break circuits as desired according to its position, in which case, of course, the contact springs 33 and 34; would be dispensed with and the two coils upon the cores would be in series with their free ends, connected directly with the external circuit, containing a device for reversing the current flow as is well understood.

Having thus described the principle of our invention and illustrated a preferred form embodying that principle, what we claim as new and desire to secure by Let-ters Patent, is:

1. In anl electro-magnetic device, a movable armature, a knife edge bearing for the armature, a pin adapted for holding the armature against the knife edge bearing, an adjustable member between the pin and the armature, said pin terminating substantially on a line with the knife edge of the bearing, and means to support the pin.

2. In an electro-magnetic device, a movable armature, a knife edge bearing for the armature, a pin adapted for holding the armature against the knife edge'bearing, an adjustable member between the pin and the armature, said pin terminating substantially on a line with the knife edge of the bearing, and adjustable means to support the pin.

3. 1n an electro-magnetic device, a movable armature of magnetic material,a knife edge bearing of magneticmaterial against which the armature is in direct magnetic cont-act and on which the armature may oscillate, a pointed pin adapted to support the armature in contact with the knife edge, a member between the pin and the armature formed with a conical cavity in which the pin rests, means to support the pointed pin, a body of magnetic material in magnetic contact with said knife edge bearing at one end, cores with which said magnetic body are in magnetic contact at the other end, coils aboutl said cores adapted to convey current, and an arm moved in unison with said armature.

4. n an electro-magnetic device, a movable armature of magnet-ic material, a knife edge bearing of magnetic material against which the armature is in direct magnetic contact and on which the armature may oscillate, a fined point to support the armature in contact with the knife edge, an adjustable member between the point and the armature, a body of magnetic material in magnetic contact with said knife edge bearing at one end, a core with which said magnetic body is in magnet-ic contact at the other end, a coil about said core adapted to convey current and thus attract. said armature to said core, and an arm moved in unison with said armature.

5. In an electro-magnetic device, a movable armature, a knife edge bearing for the armature, said armature formed with a cone shaped cavity therein having the apex of the cavity on a line with the knife edge, a pin bearing on the apenr of the cavity and means to support the pin.

6. 1n an electro-magnetic device, a movable armature, a knife edge bearing for the armature, a pointed pin adapted for holding the armature against the knife edge bearing, said pin terminating substantially on a line with the knife edge of the bearing,

iso

an adjustable member between the pin and "formed therein, said member formed With a knife edge Aand also formed With a hole therethrough, an oscillatable member in said hole attached vto said armature, means to utilize said last named member, a Apin resting `in said cone shaped cavity with its eX- ftremity in line with lthe knife edge, and

means to support said pin.

l8. n an electro-magnetic device, a yoke ott magnetic material, magnetic rods, Vlmeans fior adjustably connecting the rods land yoke and holding the rods in adj-usted position, a member madeof magnetic material fastened Yto the yoke bet-Ween the rods, a knife edge 25 bearing of magnetic material attached mag netically to the last named member, an armature ci magnetic material oscillatable on the 'knife edge and having extremities in operative relation with said magnetic rods, 30 -said varmature having contact plates thereon, contact points in :operative relation with said plates, a member insulatingly supporting said 'pointsfand also including means to support said armature, conducting coils hav- 35 ling 'two terminals surrounding said magnetic rods, one terminal of each coil 'being connected to a separate contact point, the `other terminals 0f the coils vbeing connected lone 'to fthe other forming a fline terminal, said 4 0 armature being 'connected to another line `terminal, means for utilizing motion of the armature.

MAURICE F. RCHARD C. LEATKE. Witnesses:

LILLIAN L. PHILLIPS, 'CHARLOTTE GREGoRiUs Gopies of this patent may be obtained for ve ce'nts each, 'by laddressing che Commissioner of Patents, Washngiton, |`1). C. 

